The NYPD has broken up two major drug rings operating out of housing complexes – and one of them is the Brooklyn project recently purchased by ex-Met Mo Vaughn.

Cops arrested more than 50 people involved in the operations at Noble Drew Ali Plaza in Brownsville, which Vaughn and partner Eugene Schneur purchased last week, and the Vladeck Housing Development on the Lower East Side.

Several of the drug suspects allegedly used pit bulls to intimidate residents of the complex.

Vaughn’s company plans to go ahead with its $20 million renovation of the housing project.

Schneur called the drug raid one of the hazards of buying “troubled property.”

Cops said one of those arrested, Devere Legett, who possessed more than 200 glassines of heroin, was also charged with arson for setting fire to an apartment in a dispute with the dealers.

Meanwhile, 19 people were busted at Vladeck, where undercover cops bought heroin, crack, cocaine and angel dust, police sources said. Among those arrested were members of the Latin Kings and Bloods gangs.